// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/bind.h"
#include "ui/gl/gl_bindings.h"
#include "ui/gl/gl_context_stub_with_extensions.h"
#include "ui/gl/gl_egl_api_implementation.h"
#include "ui/gl/gl_gl_api_implementation.h"
#include "ui/gl/gl_implementation.h"
#include "ui/gl/gl_implementation_osmesa.h"
#include "ui/gl/gl_osmesa_api_implementation.h"
#include "ui/ozone/public/ozone_platform.h"
#include "ui/ozone/public/surface_factory_ozone.h"

namespace gfx {

namespace {

    void GL_BINDING_CALL MarshalClearDepthToClearDepthf(GLclampd depth)
    {
        glClearDepthf(static_cast<GLclampf>(depth));
    }

    void GL_BINDING_CALL MarshalDepthRangeToDepthRangef(GLclampd z_near,
        GLclampd z_far)
    {
        glDepthRangef(static_cast<GLclampf>(z_near), static_cast<GLclampf>(z_far));
    }

} // namespace

void GetAllowedGLImplementations(std::vector<GLImplementation>* impls)
{
    impls->push_back(kGLImplementationEGLGLES2);
    impls->push_back(kGLImplementationOSMesaGL);
}

bool InitializeStaticGLBindings(GLImplementation implementation)
{
    // Prevent reinitialization with a different implementation. Once the gpu
    // unit tests have initialized with kGLImplementationMock, we don't want to
    // later switch to another GL implementation.
    DCHECK_EQ(kGLImplementationNone, GetGLImplementation());
    ui::OzonePlatform::InitializeForGPU();

    switch (implementation) {
    case kGLImplementationOSMesaGL:
        return InitializeStaticGLBindingsOSMesaGL();
    case kGLImplementationEGLGLES2:
        if (!ui::OzonePlatform::GetInstance()
                 ->GetSurfaceFactoryOzone()
                 ->LoadEGLGLES2Bindings(base::Bind(&AddGLNativeLibrary),
                     base::Bind(&SetGLGetProcAddressProc)))
            return false;
        SetGLImplementation(kGLImplementationEGLGLES2);
        InitializeStaticGLBindingsGL();
        InitializeStaticGLBindingsEGL();

        // These two functions take single precision float rather than double
        // precision float parameters in GLES.
        ::gfx::g_driver_gl.fn.glClearDepthFn = MarshalClearDepthToClearDepthf;
        ::gfx::g_driver_gl.fn.glDepthRangeFn = MarshalDepthRangeToDepthRangef;
        break;
    case kGLImplementationMockGL: {
        SetGLImplementation(kGLImplementationMockGL);
        InitializeStaticGLBindingsGL();
        break;
    }
    default:
        NOTIMPLEMENTED()
            << "Unsupported GL type for Ozone surface implementation";
        return false;
    }

    return true;
}

bool InitializeDynamicGLBindings(GLImplementation implementation,
    GLContext* context)
{
    switch (implementation) {
    case kGLImplementationOSMesaGL:
    case kGLImplementationEGLGLES2:
        InitializeDynamicGLBindingsGL(context);
        break;
    case kGLImplementationMockGL:
        if (!context) {
            scoped_refptr<GLContextStubWithExtensions> mock_context(
                new GLContextStubWithExtensions());
            mock_context->SetGLVersionString("3.0");
            InitializeDynamicGLBindingsGL(mock_context.get());
        } else
            InitializeDynamicGLBindingsGL(context);
        break;
    default:
        return false;
    }

    return true;
}

void InitializeDebugGLBindings()
{
}

void ClearGLBindings()
{
    ClearGLBindingsEGL();
    ClearGLBindingsGL();
    SetGLImplementation(kGLImplementationNone);
    UnloadGLNativeLibraries();
}

bool GetGLWindowSystemBindingInfo(GLWindowSystemBindingInfo* info)
{
    switch (GetGLImplementation()) {
    case kGLImplementationEGLGLES2:
        return GetGLWindowSystemBindingInfoEGL(info);
    default:
        return false;
    }
    return false;
}

} // namespace gfx
